Tramlining
Thread Starter
Le Mans Master
Joined: May 2008
Posts: 9,063
Likes: 2,736
2022 C3 of the Year Finalist - Modified
OK......lets call this post "ADDICTION". For those who have followed this thread from the start, you may agree with my wife's reaction, and opinion,......that I may be "crazy". So here it is.
It was a fantastic and beautiful day here in Western PA, and I launched out early this morning for a long drive. With my 15 inch YJ8 aluminum wheels and Cooper tires installed, I made my way through a series of my favorite roads. It was cool out, and my new 406 was grooving and pulling strong. As I hit the twisties without too much traffic, I started to concentrate on the fine details of how the car handled the turns, the effect of the steering wheel, and the reaction of the car. And it soon was obvious to me, that these 15 inch tires really give it up compared to the 17 inch Nitto high performance summer tires.
The first obvious characteristic is that as I pushed the steering wheel into a turn, there was a "delay" in effect, i.e, I moved the wheel, but the car did not start into the turn. Its not freeplay in the mechanism, the wheel is moving, but the initial response of the car was zero, simply because the tire is just not gripping the ground enough to initiate the turn. Its a small moment of inaction, but noticeable. So as a result, I have to move the wheel further to actually start the car into the turn. That is the first part of how the tires do not perform well.
Next, as I power into the turn, there is a sense of "softness" or body movement toward the outside of the turn. I believe its the tall sidewall / weak structure of the 15 inch tires allowing the body movement. It feels like a mushy movement away from the turn. Once all the flex of the tire is used up, the car then tracks through the turn, but on the rollout, there is an opposite mushy roll back. That mushy reaction made the car feel loose and unpredictable......when trying to push the car hard.....it borderlined on scary, and I had to slow down.
I hit the roads for a couple hours, analyzing it to death,......and decided to return home, and reinstall the 17 inch Torq Thrust wheels and Nitto tires. As I stated, everything is a compromise, but what my morning drive did was to identify that I am now "addicted" to the better performance of the 17 inch performance tires. It was simply just not as "FUN" to drive the car with the 15's. I had got a taste of better tire performance, and how the car drives with those tires,.......and the 15's just do not steer the car as well, and is LESS fun. I thought I could deal with handling compromise.....but I can't......and that is ADDICTION..
I got home, changed the wheels, and spent a couple more hours on the same roads.......and had a blast. With the back to back drives, it is clear the handling with these tires is significantly and noticeably better. With the torque of the 406, I can point and shoot into the turns, and the car moves with the wheel.....no mush, no body roll, no delay in the steering,....and when powering through the turns, the car just sticks and turns. And THAT is why I love driving this car.
So........lots of posting, to end up where I started. Yeah......wife thinks I am candidate for the mental hospital, but, just wants me to make the car the way I want it. Hope you guys get it!!! As for the tramlining,......I will work on it over time....maybe increasing caster as some suggested. For now.......I am driving. Rationalizing the compromises is just part of this love affair I have with the car. In the end.......handling became more important......as it should be with a Corvette. The combination of this torquey and sweet 406, and the better handling of the 17 performance tires, has really made this car FUN. And its the most beautiful machine on the road.
It was a fantastic and beautiful day here in Western PA, and I launched out early this morning for a long drive. With my 15 inch YJ8 aluminum wheels and Cooper tires installed, I made my way through a series of my favorite roads. It was cool out, and my new 406 was grooving and pulling strong. As I hit the twisties without too much traffic, I started to concentrate on the fine details of how the car handled the turns, the effect of the steering wheel, and the reaction of the car. And it soon was obvious to me, that these 15 inch tires really give it up compared to the 17 inch Nitto high performance summer tires.
The first obvious characteristic is that as I pushed the steering wheel into a turn, there was a "delay" in effect, i.e, I moved the wheel, but the car did not start into the turn. Its not freeplay in the mechanism, the wheel is moving, but the initial response of the car was zero, simply because the tire is just not gripping the ground enough to initiate the turn. Its a small moment of inaction, but noticeable. So as a result, I have to move the wheel further to actually start the car into the turn. That is the first part of how the tires do not perform well.
Next, as I power into the turn, there is a sense of "softness" or body movement toward the outside of the turn. I believe its the tall sidewall / weak structure of the 15 inch tires allowing the body movement. It feels like a mushy movement away from the turn. Once all the flex of the tire is used up, the car then tracks through the turn, but on the rollout, there is an opposite mushy roll back. That mushy reaction made the car feel loose and unpredictable......when trying to push the car hard.....it borderlined on scary, and I had to slow down.
I hit the roads for a couple hours, analyzing it to death,......and decided to return home, and reinstall the 17 inch Torq Thrust wheels and Nitto tires. As I stated, everything is a compromise, but what my morning drive did was to identify that I am now "addicted" to the better performance of the 17 inch performance tires. It was simply just not as "FUN" to drive the car with the 15's. I had got a taste of better tire performance, and how the car drives with those tires,.......and the 15's just do not steer the car as well, and is LESS fun. I thought I could deal with handling compromise.....but I can't......and that is ADDICTION..
I got home, changed the wheels, and spent a couple more hours on the same roads.......and had a blast. With the back to back drives, it is clear the handling with these tires is significantly and noticeably better. With the torque of the 406, I can point and shoot into the turns, and the car moves with the wheel.....no mush, no body roll, no delay in the steering,....and when powering through the turns, the car just sticks and turns. And THAT is why I love driving this car.
So........lots of posting, to end up where I started. Yeah......wife thinks I am candidate for the mental hospital, but, just wants me to make the car the way I want it. Hope you guys get it!!! As for the tramlining,......I will work on it over time....maybe increasing caster as some suggested. For now.......I am driving. Rationalizing the compromises is just part of this love affair I have with the car. In the end.......handling became more important......as it should be with a Corvette. The combination of this torquey and sweet 406, and the better handling of the 17 performance tires, has really made this car FUN. And its the most beautiful machine on the road.
Last edited by Shovels and Vettes; Jun 16, 2021 at 09:11 PM.
Drifting
Joined: Aug 2015
Posts: 1,939
Likes: 477
From: NSW, Australia
C3 of Year Finalist (track prepared) 2019
It's interesting how relative it is! I don't really suffer from bumpsteer with my car (has bumpsteer blocks and some other tweaks), but tram lining I certainly have experienced... The stock 255/60R15 BF Goodrich Radial TAs were quite bad. 255/50R17 Nitto Invos were noticeably better. 285/40R17 Continental ExtremeContact Sports were probably worse that the TAs for tram lining , but grip was a huge leap up from the Invos, which in turn were a world better than the TAs... 275/50R17 Nitto NT555 G2s that are now my street tyres have almost no tram lining at all, and grip levels between the ExtremeContact Sports and the Invos. My current track tyres though (which are road legal) are 295/35R18 Yokohama A050s, and they tram line terribly, awful to drive on a rough road... But the grip is absolutely insane. So...? Horses for courses I guess. Seems to me that sidewall height is also a factor, but an aggressive tyre will always tend to pull a bit more, all other things equal - which just makes sense really.
